There was a certain story about Duke Wortham that the world didn't know about.
A story that had made his actions so cruel and random at times.
But this was not the time for that story. What you need to know is that something's happened and the Duke came to learn that the only way out for him is the world of Dreams.
It was his only refuge in the trouble that he would face in the future and hence he sought the knowledge over the world of dreams.
But to his horror, he soon came to learn that besides a few books that mention certain figures in the past, there was nothing else.
The nightmares were Taboo subjects that were treated with fear among those who understood, while those that didn't, never even bothered to touch it out of ignorance.
It's like they never even considered it a venue of exploration, they stopped at the junction of dreams being an amalgamation of memories and experiences formed under random synapses lighting up during sleep.